New Yorkers know it often takes some divine intervention to land a great apartment. Luckily, with dozens of churches and synagogues now being partially or totally converted into luxury residential buildings, high-end apartment hunters can go straight to the source.

As congregations grapple with changing demographics, shrinking memberships, and costly upkeep of historic buildings, many religious institutions are concluding that it makes better financial sense to sell off a portion of their development rights, relocate to a more affordable site, or even close their doors for good.